实验任务:
阅读资料了解 STM32F103的RTC(实时时钟)原理,使用带SPI或IIC接口的OLED屏显模块实现以下功能:
1) 读取STM32F103C8T6 内部的时钟(年月日时分秒),日历(星期x),1秒周期,通过串口输出到PC上位机,;
2) 读取AHT20的温度和湿度,通过OLED,把年月份时分秒、日历和实时温度、湿度显示出来,2秒周期。
一、RTC时钟介绍
1.简介
RTC(Real Time Clock,实时时钟)是指安装在电子设备或实现其功能的IC(集成电路)上的时钟,通常是一个独立的定时器,即使电子设备处于关机状态也能继续运行。RTC使用一个精确的定时器和电池供电来保持时间的准确性。它通常提供了一个接口,使操作系统和其他软件可以读取和设置当前的日期和时间。RTC的原理涉及晶体振荡器、计数器、电源备份、控制逻辑和接口等主要方面。
STM32的RTC时钟是一个独立的定时器,具有连续计数的功能,在相应的软件配置下,可以提供时钟日历的功能。它包含用于管理低功耗模式的自动唤醒单元,在断电情况下仍可以独立运行,只要芯片的备用电源一直供电,RTC上的时间会一直走。此外,它还提供了两个32位寄存器,包含二进码十进数格式(BCD)的秒、分钟、小时(12或24小时制)、星期几、日期、月份和年份,以及一个具有中断功能的周期性可编程唤醒标志。系统可以自动将月份的天数补偿为28、29(闰年)、30和31天,还可以进行夏令时补偿。
2.原理
RTC内核完全独立于APB1接口,软件通过APB1接口对RTC相关寄存器访问。但是相关寄存器只在RTC APB1时钟进行重新同步的RTC时钟的上升沿被更新。所以软件必须先等待寄存器同步标志位(RTC_CRL的RSF位)被硬件置1才读。
RTC的预分频模块是一个20位的可编程分频器,它可产生最长为1秒的RTC时间基准TR_CLK。在RTC_CR寄存器中设置了相应的允许位后,每个TR_CLK周期中RTC会产生一个中断(秒中断)。该预分频模块在系统复位后自动装载,可从外部预装载寄存器读取其值。
RTC_CNT是实时时钟(RTC)的计数器寄存器。它用于存储RTC的计数值,该计数值与实时时间相对应。通过读取RTC_CNT寄存器,可以获取当前的实时时间。
二、STM32CubeMX配置生成
1.配置RCC
选择High Speed Clock(HSE)为Crystal/Ceramic Resonator
选择Low Speed Clock(HSE)为Crystal/Ceramic Resonator
2.配置SYS
在Debug中选择Serial Wire
3.配置I2C1
4.配置RTC
激活时钟和日历,初始化时间
5.配置USART
配置Mode为Asynchronous
6.配置SPI
7.配置GPIO
配置RES、DC、CS引脚
8.配置时钟
9.生成项目文件
三、代码编写
1.使用AHT20程序模板函数
修改函数使得温度读取函数在OLED上显示
void AHT20_Read_CTdata(uint32_t *ct) //??CRC??,????AHT20????????
{
volatile uint8_t Byte_1th=0;
volatile uint8_t Byte_2th=0;
volatile uint8_t Byte_3th=0;
volatile uint8_t Byte_4th=0;
volatile uint8_t Byte_5th=0;
volatile uint8_t Byte_6th=0;
uint32_t RetuData = 0;
uint16_t cnt = 0;
AHT20_SendAC();//?AHT10??AC??
Delay_1ms(80);//??80ms??
cnt = 0;
while(((AHT20_Read_Status()&0x80)==0x80))//????bit[7]?0,???????,??1,?????
{
SensorDelay_us(1508);
if(cnt++>=100)
{
break;
}
}
I2C_Start();
AHT20_WR_Byte(0x71);
Receive_ACK();
Byte_1th = AHT20_RD_Byte();//???,??????0x98,??????,bit[7]?1;???0x1C,??0x0C,??0x08???????,bit[7]?0
Send_ACK();
Byte_2th = AHT20_RD_Byte();//??
Send_ACK();
Byte_3th = AHT20_RD_Byte();//??
Send_ACK();
Byte_4th = AHT20_RD_Byte();//??/??
Send_ACK();
Byte_5th = AHT20_RD_Byte();//??
Send_ACK();
Byte_6th = AHT20_RD_Byte();//??
Send_NOT_ACK();
Stop_I2C();
RetuData = (RetuData|Byte_2th)<<8;
RetuData = (RetuData|Byte_3th)<<8;
RetuData = (RetuData|Byte_4th);
RetuData =RetuData >>4;
ct[0] = RetuData;//??
RetuData = 0;
RetuData = (RetuData|Byte_4th)<<8;
RetuData = (RetuData|Byte_5th)<<8;
RetuData = (RetuData|Byte_6th);
RetuData = RetuData&0xfffff;
ct[1] =RetuData; //??
}
2.主函数
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2023 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "rtc.h"
#include "spi.h"
#include "usart.h"
#include "gpio.h"
#include "stdio.h"
#include "oled.h"
#include "gui.h"
#include "i2c.h"
#include "dma.h"
#include "AHT20-21_DEMO_V1_3.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */
int fputc(int ch,FILE *f){
uint8_t temp[1]={ch};
HAL_UART_Transmit(&huart1,temp,1,2);
return ch;
}
void Show_Time(uint16_t Year,uint16_t Month,uint8_t Day,uint8_t Hour,uint8_t Minute,uint8_t Second)
{
GUI_ShowCHinese(0,0,16,"日期:",1);
GUI_ShowNum(48,0,Year,4,16,1);
GUI_ShowString(80,0,(uint8_t *)"/",16,1);
GUI_ShowNum(88,0,Month,2,16,1);
GUI_ShowString(104,0,(uint8_t *)"/",16,1);
GUI_ShowNum(112,0,Day,2,16,1);
GUI_ShowCHinese(0,16,16,"时间:",1);
GUI_ShowNum(48,16,Hour,2,16,1);
GUI_ShowString(64,16,(uint8_t *)":",16,1);
GUI_ShowNum(72,16,Minute,2,16,1);
GUI_ShowString(88,16,(uint8_t *)":",16,1);
GUI_ShowNum(96,16,Second,2,16,1);
}
void Show_Data(uint8_t c,uint8_t t)
{
GUI_ShowCHinese(0,48,16,"湿度",1);
GUI_ShowString(32,48,(uint8_t *)":",16,1);
GUI_ShowNum(60,48,c,2,16,1);
GUI_ShowString(84,48,(uint8_t *)"%",16,1);
GUI_ShowCHinese(0,32,16,"温度",1);
GUI_ShowString(32,32,(uint8_t *)":",16,1);
GUI_ShowNum(60,32,t,2,16,1);
GUI_ShowCHinese(80,32,16,"℃",1);
}
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
uint8_t Month,Day,Hour,Minute,Second;
uint16_t Year;
volatile int c1,t1;
uint32_t CT_data[2]={0,0};
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_RTC_Init();
MX_USART1_UART_Init();
MX_SPI1_Init();
MX_I2C1_Init();
MX_DMA_Init();
MX_I2C1_Init();
AHT20_Init();
if((AHT20_Read_Status()&0x18)!=0x18) //?????,????????
{
AHT20_Start_Init(); //??????????
Delay_1ms(10);
}
/* USER CODE BEGIN 2 */
RTC_DateTypeDef GetData; //???????
RTC_TimeTypeDef GetTime; //???????
OLED_Init();
OLED_Clear(0);
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
AHT20_Read_CTdata(CT_data);
c1 = CT_data[0]*100/1024/1024;
t1 = CT_data[1]*200/1024/1024-50;
HAL_RTC_GetTime(&hrtc, &GetTime, RTC_FORMAT_BIN);
HAL_RTC_GetDate(&hrtc, &GetData, RTC_FORMAT_BIN);
Year=GetData.Year+2000;
Month=GetData.Month;
Day=GetData.Date;
Hour=GetTime.Hours;
Minute=GetTime.Minutes;
Second=GetTime.Seconds;
printf("日期:%d/%d/%d\r\n",Year,Month,Day); //串口打印日期
printf("时间:%d:%d:%d\r\n",Hour,Minute,Second); //串口打印时间
if(GetData.WeekDay==1){
printf("星期一\r\n");
}else if(GetData.WeekDay==2){
printf("星期二\r\n");
}else if(GetData.WeekDay==3){
printf("星期三\r\n");
}else if(GetData.WeekDay==4){
printf("星期四\r\n");
}else if(GetData.WeekDay==5){
printf("星期五\r\n");
}else if(GetData.WeekDay==6){
printf("星期六\r\n");
}else if(GetData.WeekDay==7){
printf("星期天\r\n");
}
printf("\r\n"); //串口打印时间
Show_Time(Year,Month,Day,Hour,Minute,Second);
Show_Data(c1,t1);
HAL_Delay(1000);
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI|RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_ON;
RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.LSIState = RCC_LSI_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB buses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
{
Error_Handler();
}
PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_RTC;
PeriphClkInit.RTCClockSelection = RCC_RTCCLKSOURCE_LSI;
if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
{
Error_Handler();
}
}
/* USER CODE BEGIN 4 */
/* USER CODE END 4 */
/**
* @brief This function is executed in case of error occurrence.
* @retval None
*/
void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
__disable_irq();
while (1)
{
}
/* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t *file, uint32_t line)
{
/* USER CODE BEGIN 6 */
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
四、实验效果
(1)
(2)
OELD显屏2